Lowered testosterone could be MI signal

In both men and women, decreased levels of testosterone appear to precede a myocardial infarction (MI) episode, a recent study has found.

The study included 168 middle-aged participants, all of whom had suffered an MI episode, and of whom most (n=116) were men. Testosterone levels were measured in hair samples using radioimmunoassay, 1 and 3 months before an ST-elevation or non-ST-elevation acute MI (AMI) episode. A parallel group of 3,150 randomly selected general population participants was also included as a control.

In women, the mean testosterone concentration 3 months prior to an AMI attack was 1.43 pg/mg, which was not significantly different than the 1.67-pg/mg average in general-population controls (p<0.001). However, by 1 month preceding the episode, hair testosterone had dropped to 1.10 pg/mg, which fell significantly below that in controls (p<0.001).

The same interaction was reported for men, in whom the mean hair testosterone was 2.84 pg/mg 3 months before an AMI episode, as opposed to 3.05 pg/mg in controls (p=0.52). Levels decreased to 2.10 pg/mg 1 month before the attack (p<0.001).

Within-person analysis showed that MI patients experienced a substantial decrease in hair testosterone in the 2 months leading up to their infarction episode, an effect that was more prominent in men (p=0.004). In particular, testosterone dropped by 26 percent in men and 23 percent in women.

These findings are “in accordance with a stress response mechanism that has previously only been shown in animal studies. Decreased testosterone levels may be a part of the stress-related pathophysiologic process preceding a myocardial infarction,” the researchers said.